diff --git a/packages/cli/src/runtime.test.ts b/packages/cli/src/runtime.test.ts
new file mode 100644
index 00000000..c80d78a2
--- /dev/null
+++ b/packages/cli/src/runtime.test.ts
@@ -0,0 +1,201 @@
+import { describe, expect, it, vi } from 'vitest';
+import { runKtxRuntime, type KtxRuntimeDeps } from './runtime.js';
+
+function makeIo() {
+  let stdout = '';
+  let stderr = '';
+  return {
+    io: {
+      stdout: {
+        write: (chunk: string) => {
+          stdout += chunk;
+        },
+      },
+      stderr: {
+        write: (chunk: string) => {
+          stderr += chunk;
+        },
+      },
+    },
+    stdout: () => stdout,
+    stderr: () => stderr,
+  };
+}
+
+describe('runKtxRuntime', () => {
+  it('installs the requested runtime feature and prints the manifest path', async () => {
+    const io = makeIo();
+    const deps: KtxRuntimeDeps = {
+      installRuntime: vi.fn(async () => ({
+        status: 'installed',
+        layout: {
+          cliVersion: '0.2.0',
+          runtimeRoot: '/runtime',
+          versionDir: '/runtime/0.2.0',
+          venvDir: '/runtime/0.2.0/.venv',
+          manifestPath: '/runtime/0.2.0/manifest.json',
+          installLogPath: '/runtime/0.2.0/install.log',
+          assetDir: '/assets/python',
+          assetManifestPath: '/assets/python/manifest.json',
+          pythonPath: '/runtime/0.2.0/.venv/bin/python',
+          daemonPath: '/runtime/0.2.0/.venv/bin/ktx-daemon',
+        },
+        asset: {
+          wheelPath: '/assets/python/kaelio_ktx-0.1.0-py3-none-any.whl',
+          manifest: {
+            schemaVersion: 1,
+            distributionName: 'kaelio-ktx',
+            normalizedName: 'kaelio_ktx',
+            version: '0.1.0',
+            wheel: {
+              file: 'kaelio_ktx-0.1.0-py3-none-any.whl',
+              sha256: 'a'.repeat(64),
+              bytes: 10,
+            },
+          },
+        },
+        manifest: {
+          schemaVersion: 1,
+          cliVersion: '0.2.0',
+          installedAt: '2026-05-11T00:00:00.000Z',
+          asset: {
+            schemaVersion: 1,
+            distributionName: 'kaelio-ktx',
+            normalizedName: 'kaelio_ktx',
+            version: '0.1.0',
+            wheel: {
+              file: 'kaelio_ktx-0.1.0-py3-none-any.whl',
+              sha256: 'a'.repeat(64),
+              bytes: 10,
+            },
+          },
+          features: ['core', 'local-embeddings'],
+          python: {
+            executable: '/runtime/0.2.0/.venv/bin/python',
+            daemonExecutable: '/runtime/0.2.0/.venv/bin/ktx-daemon',
+          },
+          installLog: '/runtime/0.2.0/install.log',
+        },
+      })),
+    };
+
+    await expect(
+      runKtxRuntime(
+        { command: 'install', cliVersion: '0.2.0', feature: 'local-embeddings', force: true },
+        io.io,
+        deps,
+      ),
+    ).resolves.toBe(0);
+
+    expect(deps.installRuntime).toHaveBeenCalledWith({
+      cliVersion: '0.2.0',
+      features: ['local-embeddings'],
+      force: true,
+    });
+    expect(io.stdout()).toContain('Installed KTX Python runtime');
+    expect(io.stdout()).toContain('features: core, local-embeddings');
+    expect(io.stdout()).toContain('manifest: /runtime/0.2.0/manifest.json');
+    expect(io.stderr()).toBe('');
+  });
+
+  it('prints runtime status as JSON', async () => {
+    const io = makeIo();
+    const deps: KtxRuntimeDeps = {
+      readStatus: vi.fn(async () => ({
+        kind: 'missing',
+        detail: 'No runtime manifest at /runtime/0.2.0/manifest.json',
+        layout: {
+          cliVersion: '0.2.0',
+          runtimeRoot: '/runtime',
+          versionDir: '/runtime/0.2.0',
+          venvDir: '/runtime/0.2.0/.venv',
+          manifestPath: '/runtime/0.2.0/manifest.json',
+          installLogPath: '/runtime/0.2.0/install.log',
+          assetDir: '/assets/python',
+          assetManifestPath: '/assets/python/manifest.json',
+          pythonPath: '/runtime/0.2.0/.venv/bin/python',
+          daemonPath: '/runtime/0.2.0/.venv/bin/ktx-daemon',
+        },
+      })),
+    };
+
+    await expect(runKtxRuntime({ command: 'status', cliVersion: '0.2.0', json: true }, io.io, deps)).resolves.toBe(0);
+
+    expect(JSON.parse(io.stdout())).toMatchObject({
+      kind: 'missing',
+      detail: 'No runtime manifest at /runtime/0.2.0/manifest.json',
+      layout: { runtimeRoot: '/runtime' },
+    });
+  });
+
+  it('returns failure for doctor when any check fails', async () => {
+    const io = makeIo();
+    const deps: KtxRuntimeDeps = {
+      doctorRuntime: vi.fn(async () => [
+        { id: 'uv', label: 'uv', status: 'pass', detail: 'uv 0.9.5' },
+        {
+          id: 'runtime',
+          label: 'Managed Python runtime',
+          status: 'fail',
+          detail: 'No runtime manifest',
+          fix: 'Run: ktx runtime install --yes',
+        },
+      ]),
+    };
+
+    await expect(runKtxRuntime({ command: 'doctor', cliVersion: '0.2.0', json: false }, io.io, deps)).resolves.toBe(1);
+
+    expect(io.stdout()).toContain('PASS uv: uv 0.9.5');
+    expect(io.stdout()).toContain('FAIL Managed Python runtime: No runtime manifest');
+    expect(io.stdout()).toContain('Fix: Run: ktx runtime install --yes');
+  });
+
+  it('requires --yes before pruning stale runtime directories', async () => {
+    const io = makeIo();
+    const deps: KtxRuntimeDeps = {
+      pruneRuntime: vi.fn(async () => {
+        throw new Error('should not prune without --yes');
+      }),
+    };
+
+    await expect(runKtxRuntime({ command: 'prune', cliVersion: '0.2.0', dryRun: false, yes: false }, io.io, deps))
+      .resolves.toBe(1);
+
+    expect(io.stderr()).toContain('Refusing to prune without --yes');
+    expect(deps.pruneRuntime).not.toHaveBeenCalled();
+  });
+
+  it('prints stale directories during prune dry-run', async () => {
+    const io = makeIo();
+    const deps: KtxRuntimeDeps = {
+      readStatus: vi.fn(async () => ({
+        kind: 'missing',
+        detail: 'No runtime manifest at /runtime/0.2.0/manifest.json',
+        layout: {
+          cliVersion: '0.2.0',
+          runtimeRoot: '/runtime',
+          versionDir: '/runtime/0.2.0',
+          venvDir: '/runtime/0.2.0/.venv',
+          manifestPath: '/runtime/0.2.0/manifest.json',
+          installLogPath: '/runtime/0.2.0/install.log',
+          assetDir: '/assets/python',
+          assetManifestPath: '/assets/python/manifest.json',
+          pythonPath: '/runtime/0.2.0/.venv/bin/python',
+          daemonPath: '/runtime/0.2.0/.venv/bin/ktx-daemon',
+        },
+      })),
+      pruneRuntime: vi.fn(async () => ({
+        runtimeRoot: '/runtime',
+        stale: ['/runtime/0.1.0'],
+        kept: ['/runtime/0.2.0'],
+        removed: [],
+      })),
+    };
+
+    await expect(runKtxRuntime({ command: 'prune', cliVersion: '0.2.0', dryRun: true, yes: false }, io.io, deps))
+      .resolves.toBe(0);
+
+    expect(io.stdout()).toContain('Stale KTX Python runtimes');
+    expect(io.stdout()).toContain('/runtime/0.1.0');
+  });
+});
diff --git a/packages/cli/src/runtime.ts b/packages/cli/src/runtime.ts
new file mode 100644
index 00000000..61ba203d
--- /dev/null
+++ b/packages/cli/src/runtime.ts
@@ -0,0 +1,135 @@
+import type { KtxCliIo } from './cli-runtime.js';
+import {
+  doctorManagedPythonRuntime,
+  installManagedPythonRuntime,
+  pruneManagedPythonRuntimes,
+  readManagedPythonRuntimeStatus,
+  type KtxRuntimeFeature,
+  type ManagedPythonRuntimeDoctorCheck,
+  type ManagedPythonRuntimeInstallOptions,
+  type ManagedPythonRuntimeInstallResult,
+  type ManagedPythonRuntimeLayoutOptions,
+  type ManagedPythonRuntimePruneResult,
+  type ManagedPythonRuntimeStatus,
+} from './managed-python-runtime.js';
+
+export type KtxRuntimeArgs =
+  | { command: 'install'; cliVersion: string; feature: KtxRuntimeFeature; force: boolean }
+  | { command: 'status'; cliVersion: string; json: boolean }
+  | { command: 'doctor'; cliVersion: string; json: boolean }
+  | { command: 'prune'; cliVersion: string; dryRun: boolean; yes: boolean };
+
+export interface KtxRuntimeDeps {
+  installRuntime?: (options: ManagedPythonRuntimeInstallOptions) => Promise<ManagedPythonRuntimeInstallResult>;
+  readStatus?: (options: ManagedPythonRuntimeLayoutOptions) => Promise<ManagedPythonRuntimeStatus>;
+  doctorRuntime?: (options: ManagedPythonRuntimeLayoutOptions) => Promise<ManagedPythonRuntimeDoctorCheck[]>;
+  pruneRuntime?: (options: {
+    cliVersion: string;
+    runtimeRoot: string;
+    dryRun?: boolean;
+  }) => Promise<ManagedPythonRuntimePruneResult>;
+}
+
+function writeJson(io: KtxCliIo, value: unknown): void {
+  io.stdout.write(`${JSON.stringify(value, null, 2)}\n`);
+}
+
+function writeInstallResult(io: KtxCliIo, result: ManagedPythonRuntimeInstallResult): void {
+  const verb = result.status === 'ready' ? 'Using existing' : 'Installed';
+  io.stdout.write(`${verb} KTX Python runtime\n`);
+  io.stdout.write(`version: ${result.manifest.cliVersion}\n`);
+  io.stdout.write(`features: ${result.manifest.features.join(', ')}\n`);
+  io.stdout.write(`python: ${result.manifest.python.executable}\n`);
+  io.stdout.write(`daemon: ${result.manifest.python.daemonExecutable}\n`);
+  io.stdout.write(`manifest: ${result.layout.manifestPath}\n`);
+  io.stdout.write(`install log: ${result.layout.installLogPath}\n`);
+}
+
+function writeStatus(io: KtxCliIo, status: ManagedPythonRuntimeStatus): void {
+  io.stdout.write('KTX Python runtime\n');
+  io.stdout.write(`status: ${status.kind}\n`);
+  io.stdout.write(`detail: ${status.detail}\n`);
+  io.stdout.write(`runtime root: ${status.layout.runtimeRoot}\n`);
+  io.stdout.write(`version dir: ${status.layout.versionDir}\n`);
+  if (status.manifest) {
+    io.stdout.write(`features: ${status.manifest.features.join(', ')}\n`);
+    io.stdout.write(`python: ${status.manifest.python.executable}\n`);
+    io.stdout.write(`daemon: ${status.manifest.python.daemonExecutable}\n`);
+  }
+}
+
+function writeDoctor(io: KtxCliIo, checks: ManagedPythonRuntimeDoctorCheck[]): void {
+  io.stdout.write('KTX Python runtime doctor\n');
+  for (const check of checks) {
+    io.stdout.write(`${check.status.toUpperCase()} ${check.label}: ${check.detail}\n`);
+    if (check.fix) {
+      io.stdout.write(`     Fix: ${check.fix}\n`);
+    }
+  }
+}
+
+function writePrune(io: KtxCliIo, result: ManagedPythonRuntimePruneResult, dryRun: boolean): void {
+  if (result.stale.length === 0) {
+    io.stdout.write(`No stale KTX Python runtimes found under ${result.runtimeRoot}\n`);
+    return;
+  }
+  io.stdout.write(dryRun ? 'Stale KTX Python runtimes\n' : 'Removed stale KTX Python runtimes\n');
+  for (const path of dryRun ? result.stale : result.removed) {
+    io.stdout.write(`${path}\n`);
+  }
+}
+
+export async function runKtxRuntime(
+  args: KtxRuntimeArgs,
+  io: KtxCliIo = process,
+  deps: KtxRuntimeDeps = {},
+): Promise<number> {
+  try {
+    if (args.command === 'install') {
+      const installRuntime = deps.installRuntime ?? installManagedPythonRuntime;
+      const result = await installRuntime({
+        cliVersion: args.cliVersion,
+        features: [args.feature],
+        force: args.force,
+      });
+      writeInstallResult(io, result);
+      return 0;
+    }
+    if (args.command === 'status') {
+      const readStatus = deps.readStatus ?? readManagedPythonRuntimeStatus;
+      const status = await readStatus({ cliVersion: args.cliVersion });
+      if (args.json) {
+        writeJson(io, status);
+      } else {
+        writeStatus(io, status);
+      }
+      return 0;
+    }
+    if (args.command === 'doctor') {
+      const doctorRuntime = deps.doctorRuntime ?? doctorManagedPythonRuntime;
+      const checks = await doctorRuntime({ cliVersion: args.cliVersion });
+      if (args.json) {
+        writeJson(io, { checks });
+      } else {
+        writeDoctor(io, checks);
+      }
+      return checks.some((check) => check.status === 'fail') ? 1 : 0;
+    }
+    if (!args.dryRun && !args.yes) {
+      io.stderr.write('Refusing to prune without --yes. Preview with: ktx runtime prune --dry-run\n');
+      return 1;
+    }
+    const status = await (deps.readStatus ?? readManagedPythonRuntimeStatus)({ cliVersion: args.cliVersion });
+    const pruneRuntime = deps.pruneRuntime ?? pruneManagedPythonRuntimes;
+    const result = await pruneRuntime({
+      cliVersion: args.cliVersion,
+      runtimeRoot: status.layout.runtimeRoot,
+      dryRun: args.dryRun,
+    });
+    writePrune(io, result, args.dryRun);
+    return 0;
+  } catch (error) {
+    io.stderr.write(`${error instanceof Error ? error.message : String(error)}\n`);
+    return 1;
+  }
+}